Deep well pump



March 24, COFFEY DEEP WELL PUMP Filed Dec. 12, 1940 Q I fUGf/VE E COFFEY INVENTOR ATTORNEY Patented Mar. 24, 1942 UNHED STATES PATENT QFFICE DEEP WELL PUMP Eugene E. Coffey, Norman, Okla.

Application December 12, 1940, Serial No. 369,853

6 Claims.

This invention relates to an improvement in deep well pumps of the reciprocating plunger type.

It is the chief object of the invention to provide a pump of this type which is so constructed as to eliminate the use of a long string of sucker rods to reciprocate the pump plunger. The elimination of the sucker rod string means a decided reduction in the first cost of the pump installation, as well as a decided reduction in operating costs. The replacement of broken or worn sucker rods, together with the accompanying shut down of the well from production, is a very sizeable item in the cost of producing oil from any well, and the elimination of such replacements and shut downs will, conservatively, reduce production costs by more than 50%.

Another object is to produce a pump which is even more eiiicient than the generally known fluid operated type pumps, but which may be manufactured at a fraction of the cost of the fluid operated pumps which are generally available at present.

Another object is to provide a fluid operated type pump which is so constructed as to eliminate the problem of what is generally known as water hammer, and this is done by eliminating the downward travel of the column of fluid being produced from the well, as will be more fully explained hereinafter.

The details in the construction of a preferred embodiment of the invention, together with other objects attending its production, will be better understood from the following description when read in connection with the accompanying drawing, which is presented for illustrative purposes only.

The drawing is a vertical sectional view of the pump installed in a well casing, with certain rdinary pump parts illustrated by symbols only, and with the working plungers of the pump being shown approaching the upper ends of their respective strokes.

Referring to the drawing, it will be seen that a well casing is used as a means of conducting the liquid produced to the earths surface. It serves as an outer barrel for the pump. Any ordinary type packing means 6 is used to pack off between the pump intake tube 1 and the casing 5. The lower end of the intake tube 5 extends to a point below the surface of oil in the well, while its upper end communicates with the lower end of the pump working barrel 8 thru an ordinary ball check standingvalve, designated as a whole by the numeral 9. Any other type check valve may, of course, be used.

Inside, the working barrel 8 is divided into three chambers, the oil producing chamber A, the upstroke power chamber B, and the downstroke power chamber C. It will be understood from the drawing that the lower end of working barrel 8 is located just above the well bottom. The upper end of this working barrel is connected to the lower end of a string of tubing of substantially the same size as the working barrel, and this string of tubing extends upward to a point near the earths surface, where it is connected to an upper working barrel Hi. This tubing is, in reality, a part of the inner barrel.

The chambers A, B, and C, are formed within the pump barrel by suitable packing means H and I2, and the chamber C actually extends upward, thru the tubing mentioned, to the upper most end of the barrel Ill. Suitable type plungers l3 and i6 operate in chambers A and B respectively, while a plunger l5 operates in the lower end only of chamber C. All three of these plungers are connected together in tandem by a plunger rod 16, which reciprocates thru the packing means H and 12.

Another similar plunger I! is positioned and operates in the upper working barrel l0 near the upper end of the chamber 0. It is operated by a plunger rod l8, which in turn reciprocates thru a packing gland 19, which is built into a combination pump head and easing head, designated as a whole by the numeral 20. That part of chamber C between the plungers I5 and I! is completely filled with an operating liquid which is utilized to transmit downward force to the plunger [5, and which will be further referred to in detail hereinafter.

Referring now to the lower end of the pump, it will be seen that a plurality of openports 2| and 22 afford communication between the lower end of chamber B and the annular space surrounding the pump barrel 8. Also a plurality of valved ports afford fluid flow from the lower end of chamber A into the annular space surrounding the working barrel. Incidentally, it should be noted that this annular space extends from the packer 6 to the head 28, and communicates with production ports 23 and 2 3 in the head, thru which liquid is delivered from the pump. The valves which control fluid passage thru the last mentioned ports are ordinary back pressure or normally closed check valves, and are designated by the numerals 25, 26 and 27.

Operation Having explained the details of construction of one embodiment of the invention, its operation will now be explained. It should first be understood that this pump delivers only on the down stroke of the plunger I3, which movement forces fluid trapped in chamber A out thru the check. valves 25, 25, and 21, into the annular space surrounding the working barrel 8, and out thru the production ports 23 and 24. The reciprocation of the plunger IT in its barrel I near the upper end of the well is accomplished by any desired means, such as by a force pump, or an ordinary walking beam and its accompanying power source. On the down stroke of the plunger I'I, force is transmitted thru the liquid in chamber C to the plunger I5, which, thru the rod I6, forces the plungers I4 and I3 to move downward in their respective chambers, The length of stroke of these three plungers is, of course, governed by the permitted stroke of the plunger I I. It will be noted that the space between the plunger I and the packing I2, and the space between the plunger I3 and the packing II are both closed and filled with air only, which serves as a compressed air cushion at each end of the plunger stroke to prevent hammering of the plungers against the packing means II or I2.

The return of the floating plungers I3, I4 and I5 to the upper ends of their strokes (as the plunger I'I returns to the upper end of its stroke) is accomplished by providing ror an excess in the weight of the liquid column outside the pump chamber C over the weight of the liquid column inside the pump chamber C. Sufiicient excess liquid weight outside this chamber is assured by using an inner barrel of such dimensions that the cross sectional area of the annular liquid passage surrounding it is at least equal to or slightly greater than its internal cross sectional area. This differential in weight may also be increased within certain limits by filling the space between the plungers I 5 and H in chamber C with a liquid of less specific gravity than the specific gravity of the liquid being produced from the well.

Considering, then, that the weight of the liquid column outside the chamber C exceeds the weight of the liquid column inside it, it will be easily understood that at the completion of the downstroke of the plungers, the liquid outside the pump will close the valves 25, 26, and 21, and will force its way into the upstroke power chamber B thru the ports 2I and 22, and will thus force the plunger I4 to move to the upper end of its stroke. On the upstroke, the plunger I5 will lift the lighter column of liquid in chamber C, and the plunger I3 will refill the chamber A with liquid from the well bottom, thru the valve 9, as illustrated. Since the liquid production column outside the pump does not move downward during the downstroke of the plungers, there can be no sudden stoppage of the travel of this liquid column, and what is generallly known as water hammer is thus completely eliminated. There is no water hammer due to the sudden stoppage of the downward travel of the liquid column in chamber C because there is a very considerably continuous resistance to this downward travel throughout the plunger stroke.

While I have described and illustrated only one specific embodiment of my invention, I am aware that the invention may also be embodied in other forms, and I do not wish to be limited except by the prior art and by the scope of the appended claims.

I claim:

1. A deep well pump comprising: an outer barrel; an inner barrel surrounded by said outer barrel; means sealing off the space between the two barrels near their respective opposite ends; discharge ports afiording an outlet for liquid from the sealed space between the barrels; packing means dividing the inner barrel into three elongated superposed chambers, a downstroke power chamber, an upstroke power chamber, and a producing chamber; tandem floating plungers, one in each of said chambers; means connecting said floating plungers together; a power reciprocating plunger in that end of said downstroke power chamber remote from the tandem plunger therein; liquid occupying the space in the downstroke power ehainber between the two plungers and adapted to transmit motion from one to the other; open ports affording communication between the interior of the upstroke power chamber, below the path of travel of its piston, and the sealed space between the two barrels; a check valve controlled inlet port in the producing chamber adapted to permit liquid to fiow from the well into that chamber only as the plunger therein moves to the remote end thereof; and a check valve controlled outlet port afiording liquid fiow from said producing chamber into the space between the two barrels as the plunger in said chamber moves to the opposite end thereof.

2. A deep well pump adapted to operate in an upright position in a well comprising: an inner barrel divided into a downstroke power chamber, an upstroke power chamber, and a producing chamber, all arranged in end to end superposed relation; an outer barrel having discharge ports near its upper end and surrounding said inner barrel; means near the respectively adjacent opposite ends of the two barrels forming a sealed liquid passage between them, with said discharge ports at the upper end of the passage; floating tandem plungers connected together by a single rod, one plunger in each chamber; a reciprocably driven plunger in the upper end of the uppermost or downstroke power chamber; liquid occupying the space between the driven plunger and the other plunger in that chamber, and adapted to transmit power from one plunger to the other; thru-ports near the lower end of the upstroke power chamber opening into said liquid passage at a point below the path of travel of the plunger in that chamber, whereby liquid pressure in said passage may force the plunger to move upward in the chamber; a valve controlled port in the producing chamber adapted to permit the entrance only of liquid from the well; and a valve controlled port in the same chamber adapted to permit the flow of liquid only from it into said liquid passage.

3. A deep well pump adapted to operate in an upright position in a well comprising: an inner barrel divided into a downstroke power chamber, an upstroke power chamber, and a producing chamber, all arranged in end to end superposed relation; an outer barrel having discharge ports near its upper end and surrounding said inner barrel; means near the respectively adjacent opposite ends of the two barrels forming a sealed liquid passage between them, with said discharge ports at the upper end of the passage, the relative dimensions of the two barrels being such that the cross sectional area of the sealed liquid passage between the barrels is at least equal to the internal cross sectional area of the inner barrel; floating tandem plungers connected together by a single rod, one plunger in each chamber; a reciprocably driven plunger in the upper end of the uppermost or downstroke power chamber; liquid occupying the space between the driven plunger and the other plunger in that chamber, and adapted to transmit power from one plunger to the other; thru-ports near the lower end of the upstroke power chamber opening into said liquid passage at a point below the path of travel of the plunger in that chamber, whereby liquid pressure in said passage may force the plunger to move upward in the chamber; a valve controlled port in the producing chamber adapted to permit the entrance only of liquid from the well; and a valve controlled port in the same chamber adapted to permit the flow of liquid only from it into said liquid passage.

4. A deep well pump adapted to operate in an upright position in a well comprising: an inner barrel divided into a downstroke power chamber, an upstroke power chamber, and a producing chamber, all arranged in end to end superposed relation; an outer barrel having discharge ports near its upper end and surrounding said inner barrel; means near the respectively adjacent opposite ends of the two barrels forming a sealed liquid passage between them, with said discharge ports at the upper end of the passage; floating tandem plungers connected together by a single rod, one plunger in each chamber; a reciprocably driven plunger in the upper end of the uppermost or downstroke power chamber; liquid occupying the space between the driven plunger and the other plunger in that chamber, and adapted to transmit power from one plunger to the other; thru-ports near the lower end of the upstroke power chamber opening into said liquid passage at a point below the path of travel of the plunger in that chamber, whereby liquid pressure in said passage may force the plunger to move upward in the chamber; Valve means in the producing chamber adapted to alternately establish and interrupt the flow' of liquid from the well into that chamber, and to alternately and oppositely establish and interrupt the flow of liquid from that chamber into said liquid passage.

5. The combination with a well casing of a working barrel of similar length within said casing, the barrel being divided into a downstroke power chamber, an upstroke power chamber, and a producing chamber, these chambers being arranged in superposed end to end relation, the first mentioned chamber extending from the upper end of the barrel to a point near the well bottom, and the other two chambers occupying the remaining portion of the barrel below said downstroke power chamber; means near the lower end of said casing sealing the space between the casing and the pump barrel, and forming a liquid passage extending upward to the upper ends of the casing and barrel; a pair of spaced independently movable plungers in the downstroke power chamber; liquid occupying the chamber space between these two plungers for transmitting movement from one to the other; a plunger in each of the other chambers; means connecting the three lowermost plungers together to force them to reciprocate simultaneously; open ports near the lower end of the upstroke power chamber opening into said liquid passage at a point below the path of travel of the plunger in that chamber; and valve means in the producing chamber for alternately establishing and interrupting the flow of liquid from the well into that chamber, and for alternately and oppositely establishing and interrupting the flow of liquid from that chamber into said liquid passage as the plunger therein reciprocates.

6. In a deep well pump, a pair of barrels of substantially the same length, one within the other, the inner barrel extending from the earths surface into the liquid at the well bottom, and being divided into a downstrolre power chamber extending from its upper end to a point near the well bottom, an intermediate upstroke power chamber therebelow, and a producing chamber extending upward from a point near its lower end; means near the lower end of the producing chamber sealing the space between the tWo barrels and forming a liquid passage therebetween; tandem floating plungers, one in the lower end of the downstroke power chamber, and one in each of the other two chambers; a driven plunger in the upper end of the downstroke power chamber; liquid occupying the space between the two plungers in the downstroke power chamber for transmitting motion therefrom to the three tandem plungers; open ports near the lower end of the upstroke power chamber opening into said liquid passage at a point below the path of travel of the plunger in that chamber; and valve means in the producing chamber for alternately establishing and interrupting the flow of liquid from the well into that chamber, and for alternately and oppositely establishing and interrupting the flow of liquid from that chamber into said liquid passage as the plunger in the said chamber reciprocates.

EUGENE E. COFFEY. 

